A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
A busy beaver maximises some property of the computation model (e.g. execution time, memory usage, output length) subject to the constraint that it must halt.
a competition to solve a particular (usually simple) problem in the most bytes or complexity.
A challenge either involving using logic-gates as the coding language or outputting logic gates.
a number counting system using the digits 0—9 and A—F. Use this tag for challenges related to hexadecimal.
This challenge involves the manipulation of complex numbers, including parsing and printing them as well as performing complex arithmetic. This tag also encompasses generalised complex numbers like qu…
for challenges which require answers to still work when a random edit to the source code is made.
describes challenges related to factoring numbers and polynomials. Not related to the Factor esoteric programming language.
to write a solution using as many programming languages as possible.
"problems" presented to users, consisting of spelling/vocabulary challenges. The "problem" is solved when the user(s) decipher the correct spelling.
Challenge involving processing colors. It can be either for graphical output or manipulation on color codes.
For questions that relate to probability or measurements, either outputting or parsing.
Challenges that involve summarizing a large amount of data in a single, much smaller number.
for challenges involving John Conway's Game of Life.
For challenges about rearranging a set of mathematical operators or numbers to fulfill a certain expression.
for challenges involving integration or differentiation of functions.
For challenges pertaining to mathematical logic and boolean algebra.
For challenges relating in some way to encoding messages using classical (pen and paper) ciphers. For modern ciphers, such as AES, use the [encryption] tag instead.
For challenges concerning the Rubik's Cube or variations like the Pocket Cube.
Challenges relating to producing an audible output or an audio file which could then be played. If a challenge relates to textual representation of sound, it may fit better in the [music] tag.
related to the C# language. Note that challenges that require the answers to be in a specific language are generally discouraged.
for challenges related to the functional programming paradigm.
Challenges involving searching through some data to find a certain element or elements.
For challenges involving a small number of words, usually related to word generation. Do not use for "Hello, World!"-like challenges.
for challenges involving the game of tic-tac-toe (https://en.wikipedia.org/wiki/Tic-tac-toe).
For challenges with a restriction on the amount of time a submission is allowed to use.
Used for challenges where answers make reference to themselves or their characteristics, such as length or character values. Since this is a subset of the [quine] tag, many of the same restrictions ap…
A high-level data structure, made of nodes, each with a maximum of 2 children (left and right). Nodes with no children are called leaves, and two nodes with the same parent are known as siblings.
directly related to solving, creating, or otherwise working with sudoku puzzles.
related to Assembly language. Note that challenges that require the answers to be in a specific language are generally discouraged.
For challenges related to programming or markup language syntax, including but not limited to checking syntax for validity, converting from one syntax to another or fixing invalid syntax. See also the…
Used for challenges that consist of multiple sub-challenges ("holes"), somehow combining the scores into one score. (Note: combining multiple unrelated challenges together is off-topic)